Pop-up chrome....

chrome/browser/cocoa/browser_window_controller.mm

 // Copyright (c) 2009 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include <Carbon/Carbon.h>
 
 #include "base/mac_util.h"
 #include "base/scoped_nsdisable_screen_updates.h"
 #include "base/sys_string_conversions.h"
 #include "chrome/app/chrome_dll_resource.h"  // IDC_*
@@ skipping 404 matching lines @@
   if (![source isKindOfClass:[BrowserWindowController class]]) {
     return NO;
   }
 
   BrowserWindowController* realSource =
       static_cast<BrowserWindowController*>(source);
   if (browser_->profile() != realSource->browser_->profile()) {
     return NO;
   }
 
+  // Can't drag a tab from a normal browser to a pop-up
+  if (browser_->type() != realSource->browser_->type()) {
+    return NO;
+  }
+
   return YES;
 }
 
 // Move a given tab view to the location of the current placeholder. If there is
 // no placeholder, it will go at the end. |controller| is the window controller
 // of a tab being dropped from a different window. It will be nil if the drag is
 // within the window, otherwise the tab is removed from that window before being
 // placed into this one. The implementation will call |-removePlaceholder| since
 // the drag is now complete.  This also calls |-layoutTabs| internally so
 // clients do not need to call it again.
@@ skipping 242 matching lines @@
 
 - (NSInteger)numberOfTabs {
   return browser_->tabstrip_model()->count();
 }
 
 - (NSString*)selectedTabTitle {
   TabContents* contents = browser_->tabstrip_model()->GetSelectedTabContents();
   return base::SysUTF16ToNSString(contents->GetTitle());
 }
 
+// TYPE_POPUP is not normal (e.g. no tab strip)
+- (BOOL)isNormalWindow {
+  if (browser_->type() == Browser::TYPE_NORMAL)
+    return YES;
+  return NO;
+}
+
 - (void)selectTabWithContents:(TabContents*)newContents
              previousContents:(TabContents*)oldContents
                       atIndex:(NSInteger)index
                   userGesture:(bool)wasUserGesture {
   DCHECK(oldContents != newContents);
 
   // Update various elements that are interested in knowing the current
   // TabContents.
 #if 0
 // TODO(pinkerton):Update as more things become window-specific
@@ skipping 186 matching lines @@
     browser_->ExecuteCommand(command);
 }
 
 - (id)windowWillReturnFieldEditor:(NSWindow*)sender toObject:(id)obj {
   // Ask the toolbar controller if it wants to return a custom field editor
   // for the specific object.
   return [toolbarController_ customFieldEditorForObject:obj];
 }
 
 @end